ISS Pro Evolution is a classic. Maybe it\'s 10 years old now, but you can have fun with it for a couple of hours. In fact it plays so good in PSP, as if it was made for it!
Directions: Create a new folder in the PSP/GAME directory and name it: ex. SLES0001,or ULED7821, etc., and put the EBOOT.PBP file in it.